👂 Replace window.SpeechRecognition with a mock object and automate your tests
MIT License
Corti is a mock implementation of the browser’s SpeechRecognition API (aka webkitSpeechRecognition) for automated testing. It helps developers simulate speech recognition functionalities and test their applications in a controlled environment without relying on actual speech input.
💡 To easily use Speech Recognition in your own project, check out annyang.
Install corti
as a dev dependency using npm / pnpm / bun / yarn / etc:
npm install --save-dev corti
// Vitest example
import { SpeechRecognition } from 'corti';
import { describe, it, expect, beforeEach, beforeAll, afterAll, vi } from 'vitest';
beforeAll(() => {
vi.stubGlobal('SpeechRecognition', SpeechRecognition);
});
afterAll(() => {
vi.unstubAllGlobals();
});
describe('Mirror mirror on the wall', () => {
let recognition;
let spyFn;
beforeEach(() => {
recognition = new globalThis.SpeechRecognition();
spyFn = vi.fn();
recognition.maxAlternatives = 5;
recognition.onresult = spyFn;
recognition.start();
});
it('should call callback when called with a single sentence', () => {
recognition.say('Hello world');
expect(spyFn).toHaveBeenCalled();
const event = spyFn.mock.calls[0][0];
expect(event.results[0][0].transcript).toBe('Hello world');
});
it('should call callback when called with multiple sentences', () => {
recognition.say(['Hello world', 'How are you?']);
expect(spyFn).toHaveBeenCalled();
const event = spyFn.mock.calls[0][0];
expect(event.results[0][0].transcript).toBe('Hello world');
expect(event.results[0][1].transcript).toBe('How are you?');
});
});
// Jest example
const { SpeechRecognition } = require('corti');
beforeAll(() => {
global.SpeechRecognition = SpeechRecognition;
});
test('SpeechRecognition', () => {
const speech = new globalThis.SpeechRecognition();
const spyFn = jest.fn();
speech.onresult = spyFn;
speech.continuous = true;
speech.start();
speech.say('Hello world');
speech.say('Hello world');
expect(spyFn.mock.calls.length).toBe(2);
});
<script type="module">
// Mock native SpeechRecognition
import { SpeechRecognition } from 'corti.js';
window.SpeechRecognition = SpeechRecognition;
// Run some tests
const recognition = new window.SpeechRecognition();
recognition.onresult = () => console.log('I hear it!');
recognition.start();
recognition.say('Hello world');
</script>
<script src="../dist/corti.js"></script>
<script>
// Mock native SpeechRecognition
window.SpeechRecognition = corti.SpeechRecognition;
// Run some tests
const recognition = new window.SpeechRecognition();
recognition.onresult = () => console.log('I hear it!');
recognition.start();
recognition.say('Hello world');
</script>
For an example of how Corti is used in a real project, check out how SpeechRecognition is mocked and tested in Corti.
start()
abort()
stop()
addEventListener()
interimResults
lang
continuous
maxAlternatives
onstart
onend
onresult
onsoundstart
start
end
result
soundstart
SpeechRecognition
SpeechRecognitionEvent
SpeechRecognitionResultList
SpeechRecognitionResult
SpeechRecognitionAlternative
isStarted()
say()
Tal Ater: @TalAter
Licensed under MIT.